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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm64/kvm/hyp/nvhe/host.S | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/host.S')
-rw-r--r-- | arch/arm64/kvm/hyp/nvhe/host.S | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S new file mode 100644 index 0000000000..7693a6757c --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -0,0 +1,309 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 - Google Inc + * Author: Andrew Scull <ascull@google.com> + */ + +#include <linux/linkage.h> + +#include <asm/assembler.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_ptrauth.h> + + .text + +SYM_FUNC_START(__host_exit) + get_host_ctxt x0, x1 + + /* Store the host regs x2 and x3 */ + stp x2, x3, [x0, #CPU_XREG_OFFSET(2)] + + /* Retrieve the host regs x0-x1 from the stack */ + ldp x2, x3, [sp], #16 // x0, x1 + + /* Store the host regs x0-x1 and x4-x17 */ + stp x2, x3, [x0, #CPU_XREG_OFFSET(0)] + stp x4, x5, [x0, #CPU_XREG_OFFSET(4)] + stp x6, x7, [x0, #CPU_XREG_OFFSET(6)] + stp x8, x9, [x0, #CPU_XREG_OFFSET(8)] + stp x10, x11, [x0, #CPU_XREG_OFFSET(10)] + stp x12, x13, [x0, #CPU_XREG_OFFSET(12)] + stp x14, x15, [x0, #CPU_XREG_OFFSET(14)] + stp x16, x17, [x0, #CPU_XREG_OFFSET(16)] + + /* Store the host regs x18-x29, lr */ + save_callee_saved_regs x0 + + /* Save the host context pointer in x29 across the function call */ + mov x29, x0 + +#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL +alternative_if_not ARM64_HAS_ADDRESS_AUTH +b __skip_pauth_save +alternative_else_nop_endif + +alternative_if ARM64_KVM_PROTECTED_MODE + /* Save kernel ptrauth keys. */ + add x18, x29, #CPU_APIAKEYLO_EL1 + ptrauth_save_state x18, x19, x20 + + /* Use hyp keys. */ + adr_this_cpu x18, kvm_hyp_ctxt, x19 + add x18, x18, #CPU_APIAKEYLO_EL1 + ptrauth_restore_state x18, x19, x20 + isb +alternative_else_nop_endif +__skip_pauth_save: +#endif /* CONFIG_ARM64_PTR_AUTH_KERNEL */ + + bl handle_trap + +__host_enter_restore_full: + /* Restore kernel keys. */ +#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL +alternative_if_not ARM64_HAS_ADDRESS_AUTH +b __skip_pauth_restore +alternative_else_nop_endif + +alternative_if ARM64_KVM_PROTECTED_MODE + add x18, x29, #CPU_APIAKEYLO_EL1 + ptrauth_restore_state x18, x19, x20 +alternative_else_nop_endif +__skip_pauth_restore: +#endif /* CONFIG_ARM64_PTR_AUTH_KERNEL */ + + /* Restore host regs x0-x17 */ + ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] + + /* x0-7 are use for panic arguments */ +__host_enter_for_panic: + ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] + + /* Restore host regs x18-x29, lr */ + restore_callee_saved_regs x29 + + /* Do not touch any register after this! */ +__host_enter_without_restoring: + eret + sb +SYM_FUNC_END(__host_exit) + +/* + * void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); + */ +SYM_FUNC_START(__host_enter) + mov x29, x0 + b __host_enter_restore_full +SYM_FUNC_END(__host_enter) + +/* + * void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, + * u64 elr, u64 par); + */ +SYM_FUNC_START(__hyp_do_panic) + /* Prepare and exit to the host's panic funciton. */ + mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ + PSR_MODE_EL1h) + msr spsr_el2, lr + adr_l lr, nvhe_hyp_panic_handler + hyp_kimg_va lr, x6 + msr elr_el2, lr + + mov x29, x0 + +#ifdef CONFIG_NVHE_EL2_DEBUG + /* Ensure host stage-2 is disabled */ + mrs x0, hcr_el2 + bic x0, x0, #HCR_VM + msr hcr_el2, x0 + isb + tlbi vmalls12e1 + dsb nsh +#endif + + /* Load the panic arguments into x0-7 */ + mrs x0, esr_el2 + mov x4, x3 + mov x3, x2 + hyp_pa x3, x6 + get_vcpu_ptr x5, x6 + mrs x6, far_el2 + mrs x7, hpfar_el2 + + /* Enter the host, conditionally restoring the host context. */ + cbz x29, __host_enter_without_restoring + b __host_enter_for_panic +SYM_FUNC_END(__hyp_do_panic) + +SYM_FUNC_START(__host_hvc) + ldp x0, x1, [sp] // Don't fixup the stack yet + + /* No stub for you, sonny Jim */ +alternative_if ARM64_KVM_PROTECTED_MODE + b __host_exit +alternative_else_nop_endif + + /* Check for a stub HVC call */ + cmp x0, #HVC_STUB_HCALL_NR + b.hs __host_exit + + add sp, sp, #16 + /* + * Compute the idmap address of __kvm_handle_stub_hvc and + * jump there. + * + * Preserve x0-x4, which may contain stub parameters. + */ + adr_l x5, __kvm_handle_stub_hvc + hyp_pa x5, x6 + br x5 +SYM_FUNC_END(__host_hvc) + +.macro host_el1_sync_vect + .align 7 +.L__vect_start\@: + stp x0, x1, [sp, #-16]! + mrs x0, esr_el2 + ubfx x0, x0, #ESR_ELx_EC_SHIFT, #ESR_ELx_EC_WIDTH + cmp x0, #ESR_ELx_EC_HVC64 + b.eq __host_hvc + b __host_exit +.L__vect_end\@: +.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) + .error "host_el1_sync_vect larger than vector entry" +.endif +.endm + +.macro invalid_host_el2_vect + .align 7 + + /* + * Test whether the SP has overflowed, without corrupting a GPR. + * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit + * of SP should always be 1. + */ + add sp, sp, x0 // sp' = sp + x0 + sub x0, sp, x0 // x0' = sp' - x0 = (sp + x0) - x0 = sp + tbz x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@ + sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 + sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp + + /* If a guest is loaded, panic out of it. */ + stp x0, x1, [sp, #-16]! + get_loaded_vcpu x0, x1 + cbnz x0, __guest_exit_panic + add sp, sp, #16 + + /* + * The panic may not be clean if the exception is taken before the host + * context has been saved by __host_exit or after the hyp context has + * been partially clobbered by __host_enter. + */ + b hyp_panic + +.L__hyp_sp_overflow\@: + /* Switch to the overflow stack */ + adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0 + + b hyp_panic_bad_stack + ASM_BUG() +.endm + +.macro invalid_host_el1_vect + .align 7 + mov x0, xzr /* restore_host = false */ + mrs x1, spsr_el2 + mrs x2, elr_el2 + mrs x3, par_el1 + b __hyp_do_panic +.endm + +/* + * The host vector does not use an ESB instruction in order to avoid consuming + * SErrors that should only be consumed by the host. Guest entry is deferred by + * __guest_enter if there are any pending asynchronous exceptions so hyp will + * always return to the host without having consumerd host SErrors. + * + * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the + * host knows about the EL2 vectors already, and there is no point in hiding + * them. + */ + .align 11 +SYM_CODE_START(__kvm_hyp_host_vector) + invalid_host_el2_vect // Synchronous EL2t + invalid_host_el2_vect // IRQ EL2t + invalid_host_el2_vect // FIQ EL2t + invalid_host_el2_vect // Error EL2t + + invalid_host_el2_vect // Synchronous EL2h + invalid_host_el2_vect // IRQ EL2h + invalid_host_el2_vect // FIQ EL2h + invalid_host_el2_vect // Error EL2h + + host_el1_sync_vect // Synchronous 64-bit EL1/EL0 + invalid_host_el1_vect // IRQ 64-bit EL1/EL0 + invalid_host_el1_vect // FIQ 64-bit EL1/EL0 + invalid_host_el1_vect // Error 64-bit EL1/EL0 + + host_el1_sync_vect // Synchronous 32-bit EL1/EL0 + invalid_host_el1_vect // IRQ 32-bit EL1/EL0 + invalid_host_el1_vect // FIQ 32-bit EL1/EL0 + invalid_host_el1_vect // Error 32-bit EL1/EL0 +SYM_CODE_END(__kvm_hyp_host_vector) + +/* + * Forward SMC with arguments in struct kvm_cpu_context, and + * store the result into the same struct. Assumes SMCCC 1.2 or older. + * + * x0: struct kvm_cpu_context* + */ +SYM_CODE_START(__kvm_hyp_host_forward_smc) + /* + * Use x18 to keep the pointer to the host context because + * x18 is callee-saved in SMCCC but not in AAPCS64. + */ + mov x18, x0 + + ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] + ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] + + smc #0 + + stp x0, x1, [x18, #CPU_XREG_OFFSET(0)] + stp x2, x3, [x18, #CPU_XREG_OFFSET(2)] + stp x4, x5, [x18, #CPU_XREG_OFFSET(4)] + stp x6, x7, [x18, #CPU_XREG_OFFSET(6)] + stp x8, x9, [x18, #CPU_XREG_OFFSET(8)] + stp x10, x11, [x18, #CPU_XREG_OFFSET(10)] + stp x12, x13, [x18, #CPU_XREG_OFFSET(12)] + stp x14, x15, [x18, #CPU_XREG_OFFSET(14)] + stp x16, x17, [x18, #CPU_XREG_OFFSET(16)] + + ret +SYM_CODE_END(__kvm_hyp_host_forward_smc) + +/* + * kvm_host_psci_cpu_entry is called through br instruction, which requires + * bti j instruction as compilers (gcc and llvm) doesn't insert bti j for external + * functions, but bti c instead. + */ +SYM_CODE_START(kvm_host_psci_cpu_entry) + bti j + b __kvm_host_psci_cpu_entry +SYM_CODE_END(kvm_host_psci_cpu_entry) |